Manufacture of artificial yarns or other materials



Jan. 3, 1939. DREYFUS r AL 2,142,721

MANUFACTURE OF ARTIFICIAL YARNS OR OTHER MATERIALS Original Filed Feb.1, 1935 Patented Jan. 3, 1939 UNI-TED STATES PATENT OFFICE MANUFACTUREOF ARTIFICIAL YARNS OR OTHER MATERIALS Henry Dreyfus, London, and DonaldFinlayson, Spondon, near Derby, England, assignors to CelaneseCorporation 01 America, a corporation oi Delaware Original applicationFebruary 1, 1935, Serial No. 4,511. Divided and this application January18, 1937, Serial No. 121,150. In Great Britain February 2, 1934 10Claims. (Cl. 8-132) lose ester or ether and having improved properties,particularly improved tensile strength,

The application is a-divisional application of our application S. No.4,511 filed February 1, 1935.

The production of materials of the above character, and particularlyfilaments and similar textile materials, having an increased tensilestrength is of considerable importance from the commercial point ofview. The processes which have been hitherto proposed with this objecthave involved subjecting the threads or other materials to astretching'operation, and in order to obtain substantial increases intensile strength it has been considered necessary to subject thematerials to the action of liquids which are solvents or swelling agentsfor the materials, for example dioxane, acetone, acetic acid,and'diacetone alcohol, all applied for example in aqueous solution. Ithas also been suggested to use such liquids in the vapour state.

. square inch above atmospheric pressure. The

best conditions for treatment are dependent upon the degree of stretchrequired and the rate of stretching and upon a number of factors to bereferred to hereinafter. For relatively low degrees of stretch thepressure may be only slightly above atmospheric pressure, for exampleonly a few pounds above atmospheric pressure. I

By the new process degrees of stretch of 200% or more may be obtained,particularly when the water is employed at a temperature above 125 0.,for example stretches of many hundreds per cent.

By employing appropriate temperatures for giving high degrees ofstretch, filaments and threads of very fine denier and similarly thinfoils, films and the like may be obtained.

Textile materials to be treated in accordance with the invention may bethreads or other materials composed of continuous filaments, or may bespun yams made of short or more or less long lengths of filament,and'may be obtained by-cutting up or by any other suitable process, iorexample the process of U. S. Patent No. 2,077,078. The materials mayinitially have any desired lustre from a high lustreto medium lustre orapproximately the lustre of natural silk or even a dull lustre or nolustre at all. Thus, the materials may have a low lustre due to thepresence therein of titanium dioxide or other pigments. Preferably thematerials on entering the hot Water are substantially free from volatilesolvents.

The operation maybe carried out on the materials in any suitable form;for example threads may be stretched in hank form, for instance betweenrollers positioned in a vessel containing the hot water. Preferably,however, stretching of the materials is effected during the course oftheir travel from one point to another. The .treatment may be applied toa single thread, e. g. during winding from a cake or cheese orbobbin onto a bobbin, or it may be applied to a .number of threadssimultaneously. Thus, artificial threads may be stretched while runningfrom one creel of bobbins to another creel. When simultaneouslystretching a number of threads, it is advantageous to arrange thethreads in parallel alignment in the form of a sheet or, if desired, inthe form of two parallel sheets.

The stretching operation may be carried out so that the desired degreeof stretch is obtained ina single stage of stretching or, if desired,intermediate rollers or other stretching devices may be provided so asto carry out the stretch in more than one stage.

Apparatus enabling the stretching to be car ried out is described in ourco-pending application No. 47,798 filed November 1, 1935. Broadly theapparatus comprises a substantially closed chamber for the hot waterprovided with heating 7 means for water in the chamber and with one ormoreinlet and outlet orifices for the materials, associated with meansfor stretching the materials while in the chamber. may be provided witha source of supply of water under pressure and means for removing thewater continuously. The water chamber may further be provided with apressure-relief valve, a water drain-ofl and a pressure gauge. The waterchamber is constructed to resist the required pressure and the inlet andoutlet orifices for the materials are sufliciently small to enable thepressure to be maintained.

The accompanying drawing illustrates diagram-- matically a suitableapparatus for carrying out the stretching with hot water under pressure.

Figure 1 shows a longitudinal view of the ap- The chamber paratus,largely in section, while Figure 2 shows a horizontal cross-section ofthe hot water chamber.

The threads I from a creel oi bobbins 2 are carried through nip rollers3 into the hot water chamber 4, are drawn therethrough by nip rollers 5and taken up on a creel of bobbins 6. To the hot water chamber 4 aresecured closure plates 1 and 8 suitably perforated for the passage ofthe threads as illustrated in Figure 2. Water enters the chamber 4 by apipe 9 from a suitable reservoir (not shown) maintained under pressure,for example by means of compressed air, and leaves the chamber by a pipeIll. The chamber 4 is further provided with a pressure gauge H and witha steam heating coil H for maintaining the desired temperature. catchtrays, illustrated diagrammatically at l3 and I4, provided with drains,serve to catch the water exuded through the orifices in the closureplates 1 and 8. A drain I5 is provided for draining the hot waterchamber 4, for example for threading up the apparatus.

The length of thread subjected to the action of the hot water may bequite short and good stretching may be obtained with a length of lessthan one foot. However, it is preferable to extend the length of the hotwater chamber to some feet, for example 3-6 feet or more, the preciselength depending upon the temperature and the amount and rate ofstretching.

For any particular degree of stretch and rate of stretching, a range oftemperatures is available. The best temperature at which to work '5depends upon a number of factors, including the twist on the initialthread which for quick stretching should be as small as possible, the

nature of the cellulose derivative under treat- -ment, materials made ofhigh viscosity cellulose derivatives requiring in general rather highertemperatures than materials made of low viscosity cellulose derivatives.Furthermore, the size of the inlet and outlet orifices may have aninfluence upon the optimum temperature for any particular degree andrate of stretching. As previously indicated, the inlet and outletorifices are sufllciently small to enable the pressure to be maintained.Their size may be varied with the denier of the threads undergoingstretching. In general, the temperature is preferably adjusted to enableas low a stretching tension as possible to be used.

The stretched materials may be subjected to any desired after-treatmentprocesses. Thus, the filaments, threads and other materials may betreated with shrinking agents to improve their extensibility. Suitableprocesses for this 'purpose are described in U. S. Patent No. 2,058,422.In particular reference is made to the latent solvents referred to inthat specification, for example a mixture of methylene chloride andbenzene.

Again, stretched cellulose ester materials may be subjected to processesof saponification. The saponification may be such as to lead to arelatively small loss in weight, for example suflicient to give thematerials an aflinity for cotton dyestufls, or may be complete orsubstantially complete, i. e. so as toeliminate all or substantially allof the ester content. The saponification may be effected under suchconditions of tension that shrinkage takes place during or immediatelyafter the saponification, this being advantageous from the point of viewof the extensibility of the products.

Suitable Such further {treatments may be carried out as operationsseparate from the stretching or may be carried out continuously withstretching. Thus, for example, the invention includes a continuousoperation which involves first stretching and then shrinking, forexample a stretching to several hundreds per cent. of the originallength of the material followed by a shrinking by [-12% of the length ofthe stretched material; a continuous operation involving stretchingfollowed by saponification; and a continuous operation involvingstretching, finally saponification.

'While the invention has been described above more particularly withreference to cellulose acetate, it may also be applied to materialscontaining other cellulose esters or ethers, for example celluloseformate, cellulose. propionate, cellulose butyrate, methyl, ethyl, orbenzyl cellulose, or mixtures of esters and/or ethers or of mixedesters, ethers, or ether-esters. Furthermore, ribbons, foils, films,sheets and the like may be stretched by the processes described, and inthe case of foils, films and the like the stretching may be eitherlongitudinal and/or lateral or a lateral tension may be appliedsufficient to prevent lateral shrinkage during the application of rialshave an improved tenacity, which comprises stretching the materials to adegree greater than the dry extensibility thereof in hot water underpressure at a temperature between and C. during their travel from onepoint to another.

3. Process for improving the strength of filaments, threads and similartextile materials and of foils, films and the like made of celluloseacetate, which comprises stretching the materials to a degree greaterthan the dry extensibility thereof in hot water under pressure at atemperature between 100 C, and 110 C. during their travel from one pointto another.

4. Process for improving the strength of filaments, threads and similartextile materials and of foils, films and the like made of an organicsubstitution derivative of cellulose, which comprises stretching thematerials to a degree greater than the dry extensibility thereof in hotvwater under pressure at a temperature of 110 to C. during their travelfrom one point to another.

5. Process for improving the strength of filaments, threads and similartextile materials and of foils, films and the like made of celluloseacetate, which comprises stretching the materials to a degree greaterthan the dry extensibility thereof in hot water under pressure at atemperature of, 110 to 125 C. during their travel from one point toanother.

6. Process for improving the strength of filaments, threads and similartextile materials and of foils, films and the like made of an organicsubstitution derivative of cellulose, which comprises stretching thematerials in hot water under pressure at a temperature above 125 C.

shrinking, and

7. Process for improving the strength of filaments, threads and similartextile materials and of foils, films and the like made of celluloseacetate, which comprises stretching the materials to a degree greaterthan the dry extensibility thereof in hot water under pressure at atemperature above 125 C. during their travel from one point to another.

8. Process for improving the strength of filaments, threads and similartextile materials made of cellulose acetate, which comprises stretchingthe materials to at least 200% of their original length during thecourse of their travel through hot water under pressure at a temperatureof 15 '110 to 125 C. v,

9. Process for improving the strength of filaments, threads and similartextile materials made of cellulose acetate, which comprises stretchingthe materials to at least 200% of their original length during thecourse of their travel through hot water under pressure at a temperatureabove 125 C.

10. Process for improving the strength of fila merits, threads andsimilar textile materials made of an organic substitution derivative ofcellulose, which comprises stretching the materials to at least 200% oftheir original length during the course of their travel'through hotwater'under pressure at a temperature above 125 C.

HENRY DREYFUS. DONALD F'INLAYSON.

